1. Field of the Invention
The invention relates to a key cylinder device and, in particular, to a key cylinder device provided with tumblers to be aligned by insertion of a key.
2. Description of the Related Art
A key cylinder device used for, e.g., a vehicle steering lock device is known (see e.g., JP-B-3346706).
The key cylinder device disclosed in JP-B-3346706 is provided with a cylinder lock in which an inner cylinder is inserted into an outer cylinder from the rear side (steering lock device side) so as to be rotatable. The cylinder lock is configured such that a lock pin provided to protrude from the inner surface of the outer cylinder butts against a flange-shaped portion formed on the rear side of the inner cylinder while the flange-shaped portion of the inner cylinder butts against a step portion formed inside a body of the steering lock device, and the inner cylinder is thereby prevented from moving toward the rear side.
In the inner cylinder of the cylinder lock, key checking tumblers movable in a radial direction of the inner cylinder are resiliently held in plural tumbler holding holes providing passages across a key insertion hole which extends in a rotation axis direction.
When the cylinder lock is unlocked, the protruding end portions of the tumblers are withdrawn from recesses on the inner surface of the outer cylinder by insertion of a key into the key insertion hole to allow the inner cylinder to rotate, and the cylinder lock is thereby unlocked. On the other hand, when the cylinder lock is locked, the protruding end portions of the tumblers are advanced into the recesses of the outer cylinder by extraction of the key from the key insertion hole to prevent the inner cylinder from rotating, and the cylinder lock is thereby locked.